Honing tool



HONING TOOL Filed July l5, 1932 ?atenter jan.

'UNITED STATES Maasai Our invention relates to honing tools andparticularly to a honing tool of the rigid type which is retained inrigid extension of the driving spindle.

The trend of the art in cylinder grinding andV honing has been towardtools which may be operated at high speed to not only reduce the time ofthe grinding operation but also provide abetter and finer nish on thewall of the cylinder. When the speed of the conventional. tool wasincreased, considerable difficulty was experienced because ofthewhipping of the tool relative to the cylinder wall which required thetool to be stopped before it was removed from the cylinder to pre' ventthe abrading elements thereof from striking the side wall and destroyingits nish.. l

In practicing this invention we provide 4a tool which is employedprimarily for high speed opera-4 tion and which is so constructed as topermit the tool to be removed from the cylinder vwall during its highspeed operation without there being any danger of the abrading elementsofl the 4tool or other portions thereof striking the cylinder Wall tomar the finish thereof. A rigid spindle is employed on the tool having aconnecting portion.- k which is engaged by the driving spindle of themachine in such manner as to forrn arigid yconnection therewith to havethe tool retained inl fixed extended relation to the spindle,A The rigidspindleof the tool prevents the whipping of the -grinding end ofthecylinder and the abrasive elements from contacting with thevside of thecyl-k inder Wall when in contracted position.

To permit the abrading elements to adjust relation of the spindlethereto. `The tool isprovided with a guide plate on its lower end toprotect the abrasive elements from striking the top of the cylinderblock when the tool is inserted into the bore thereof and springs areutilized for retaining the abrasive elements retracted against theirseats adjacent to the spindle. The springs are employed at the top andbottom ends of the abrasive elements and are provided of differentstrength. The springat the top of theelements is of less strength thanthe spring employed in the bottom thereof to have the upper end of theabrasive elements move outwardly in case"the conical vadjusting elemento f the' tool is -inadvertentlymoved, to thereby permit the lower end ofthe eiementstoenter the cylinder and tohave K the elements'thereaftermoved into parallelaligned relation as the movement into the cylinderprogresses. This is made possible by employingY a j point contactbetweenthe abrasive element hold- 5' v y ers and the adjusting element .tupermit the tilting of the holders relative thereto which is alsonecessary to permit the complete universal vadjustment of the holdersrelative to the unaligned` spindle. l ,10

Accordingly, 'the main objects of our. invention Y are; to provide ahoning tool with a solidspindle which permits the tool to be operated ata vhigh n speed; to provide an :adjusting element for the abrasivestones which moves thestones laterallyA 15 of thev spindle and which`permits theistones to center themselves relative to a cylinder bore ir.`respective vof a slight voff-center relation of`- the spindle thereto;`to provide springs of relative strength, in thenatureofgarter-springs,for re'- 20 taining the abrasive stonesinretrieved position intheir seat; to mount the spring,` of.4 greaterkstrengthat the lower end of the 'abrasive elements which will beretained in retrieved .positionwhen v pressure is applied totheexpanding elementsr 25` during the time the hone` is inserted into acylder; to provide aguide plate at the end` of the tool whichpreventsthe` abrasiveelement from striking the't'op of the cylindervwall;v and, in general, to provide a honing tool which may bev op- 30erated at high speed to rapidly machinethewall of a cylinder and toproduce an exceedingly vhigh finish thereto.-

' Other objects and features ofnovelty of `my invention will be veithervspecifically pointed out 35 or will become apparent when referring, fora better understanding ofour invention, to the.

following description in conjunction with the accompanying drawing,wherein: f

j Figure l is a view, partly in section and partly 40 in'elevation, of ahoning tool embodying features o f my invention, and l .A .Y Y

Fig. 2 is a sectional viewof the structure illusf Referring to thefigures, the honing toolv 5 com- 45 prises a solid spindle 6supporting'an` adjustable mechanism 1, a pressure exerting device 8 andacutting head 9 all of which are revolvable jw'ithl the spindle' andmovable longitudinally thereof The upper .endv of `the spindle isrigidlyjsecured to afreta'ining `and connectingfhead Ily through PATENTome;

thereof. A pin |4 extends through the portion I2 in engagementkwithslots in the shank I3 for supporting the tw'o elements against relativelon- The nut |1 is screwed upon a threaded extension I8 of a springenclosing housing I9 which is retained against rotation relative'to the"spindle 6 by a pin 2| which projects within a slot 22 providedlongitudinally of the spindle.

The cam collar I5 is retainedrelative to the member Il on the spindle 6against downward displacement by a washer 23. The upward bias of thecollar I5, effected through the spring enclosingwhousing I9, the nut I1andthe member I6, is applied to a plurality of ball bearings 24,positioned between the upper surface of the collar |5 and the lowersurface of the head The ball bearings 24 reduce the frctional engagementbetween the two members and permit the ready adjustment of the membersI5 for a. purpose which will beexplained hereinafter.v 'Ihe cam carryingwasherv I6 is provided with a tongue 25 which projects within the slot22v to prevent the washer from rotating. A plurality of recesses ornotches 26 are provided on both sides of the element I6 to effect alocking engagement with spring biased-plungers 21 provided in themembers I5 and I1 which are locked in predetermined position thereby.

The member I1 is provided with a plurality of camming surfaces 28, whichas illustrated in Fig. 1 are normally in nested relation with aplurality of 'camming surfaces 29 provided on the member I6. When theadjustable collar |5 is rotated about the spindle 6 relative to thewasher I6 the camming surfaces 28 and 29 pass upon each other to effecta downward thrust to the member I6 and therefore to the elements inengagement therewith. These elements include the adjustable nuts I1 andthe spring enclosing housing 9 which, when moved downwardly apply a biasto a lspring 3| supported within a cage 32 which is positioned about thespindleA 6.- r.l'he spring herein' illustrated is of preferredconstruction and is described and claimed in the copending applicationof F. M. Kern, Serial No. 521,092, filed March 9, 1931, and assigned tothe assignee of the present invention. 1 n

The cage 32 limits the expansion of the spring and therefore permits theabrading elements .of the head 9 to be moved a predetermined amount,

- after which the spring stress will be ineffective because of thecomplete expansion of the spring within the cage 32. A washer 33 ismounted within thehousing I9 above the lspring cage 32 having an annulardownwardly extending ange which projects over the cage in position toengage the spring 3| to apply aV predetermined compression thereto. Aspring 34 is provided about the spindle 6,`resting on a shoulder 35thereof, for biasing the washer 33 upwardly out of engagement with thespring 3| when the camming elements 28 vand 29 are in nested `relationas illustrated in the figure. Y

Below the spring cage 32 and in intimate contact therewith is providedan annular washer 36 having extending fingers 31 thereon which areguided in slots 38 in the'sides of the spindle 6 to prevent the fingersfrom rotating relative to the pindle E; In this construction, thedownward movement of the washer 33 stresses the spring 3| which appliesapressure through the cage 32 and the washer 36 to the lingers 31 tomove them downwardly relative to the spindle 6.

A camming member 4|, of irusto conical shape, is positioned aboutthelower portion of the spindle 6 for movement longitudinally thereofIeffected by the thrust applied to the fingers 31. Above and below thecamming member 4I, spiders 42 and 43 are secured in fixed relation tothe spindle 6 by keys 44 and 45.

As illustrated in-Fig. 2 the spiders are provided Awith a plurality ofslots 46 for receiving the shoes 41 which support the abrading elements48. The abrading elements are of a form similar to that described in theco-pending application of G. M. Calvert, Serial No. 574,381, iiledNovember 11, 1931, and assigned to the assignee of the presentapplication and will not be further described. The shoes 41'are providedwith cam engaging surfaces 49 by which the abrading elements areadjusted laterally of the spindle 6 when the camming member 4| is movedlongitudinally thereby. A spring 5| is provided below the camming member4| in abuttingrelation to the spider 43 for-moving the member 4| andfingers 31 upwardly when the camming collar I5 is moved to a positionyillustrated in the drawing. The camter spring 54, positioned at thebottom of the tool,

is of greater strength than the spring 55 positioned on the upper end ofthe abrasive elements. When the adjusting nut I1 and the housing I9 aremoveddownwardly against the bias of the spring 5|, the camming member 4|is moved downwardly to cause the abrading elements to be moved. radiallyof the spindle. In the present construction, because of the greatertension in the spring 54than in the spring 55, the upper ends of theabrading elements 48 will be moved outwardly while the lower ends willbe retained in substantially their collapsed position. The purpose ofthis construction is to prevent the lowerend of the head 9 from beingexpandedv when the tool is inserted within a cylinder bore whenr theadjustable portion of the mechanism has been moved downwardly.

l As a further precaution in preventing the abrading element fromlstriking the top ofthe cylinder housing when being inserted in a borethereof, we provide a guiding member 56 which is secured to theend ofthe tool by a nut 51. l. The guiding member is of a diameter substantialto that of the area encompassed by the abrading elements to therebyprevent the elements from strikingv against the top of the cylinderhousing when the honing tool is being inserted within the bore.

.Referring again to'Fig. 1, it will be noted that 4the camming memberV4I has a greater internal The operation of our tool will now bedescribed. The tool is first assembled on the shank I3 through theinsertion of the projection I2 in the recess thereof and turned to havethe pin I4 supported within the slots communicating with the shankrecess. The cylindrical extension I2 fits snugly within the recess tohave the tool positioned as a rigid extension of the spindle. The nut I1is then adjusted to effect the proper maximum expansion of the abradingelements 48 which will occur when the camming member I5 has been turnedto have the cam 28 ride upon the cam 29` The camming nut I5 is thenturned to collapsed position, which is that illustrated in Fig. 1, andthe shank I3 is lowered to have the abrading elements enter the bore.

The camming member I5 is again operated to have the surface 28 ride uponthe surface 29 to expand the abrading elements 48 against the bore to bemachined through the downward thrust applied to the adjusting nut I1 andthe housing I9, after which the spring 3l is compressed.- The honingtool is then rotated and the abrading elements machine the walls of thecylinder bore. During the machining operation, the bias of the spring 3Ieiects a downward thrust to the fingers 31 and the camming member 4|-,to force theabrading elements 48` outwardly of the spindle 6. Theexpansion of the elements 48 continues until such time as the spring 3|has expanded against the flanges of the spring cage 32 after which nofurther downward movement of the camming member 4I obtains and thelateral movement of the abrasive elements ceases.

During the operation of the tool at a time when the spindle 6 is inoffset relation to the cylinder br c, the clearance between the cammingmember 4I and the spindle 6 and the ability of the holders 41 to tiltrelative to the member 4I permits the abrasive elements 48 to centerthemselves at all times relative to the cylinder bore, to effect thecorrect machining of the bore irrespective of the oir-center rotation ofthe spindle 6 therewith. After the machining operation, the rotation ofthe honing tool may be stopped and the camming member I5 turned to thecollapsed position, illustrated in Fig. 1, and the tool Withdrawn fromwithin the cylinder bore.

By having garter springs of different tension at the ends of theabrading elements, we prevent the accidental expansion of the bottomportion of the abrading elements when the adjustable portion of the-tool is moved downwardly, to prevent the ends of the abrading elementfrom striking against the top of the cylinder block. In like manner theguide plate 56 prevents thev striking of the abrading elementsagainstthe top of the cylinder block when the tool is inserted within thecylinder bore, the plate being provided with sloping sides 58 for aidingin guiding the tool therewithin.

While we have described a tool of the manually adjustable type as beingprovided With the rigid spindle 6, it is to be understood that the sameprinciples embodied therein may be applied to a fll automatic tool inwhich the expansion and the collapse of the honing elements occursautomatically when the tool is raised or lowered relative to itscylinder bore. Such an automatic tool is illustrated and described inthe co-pending application of F. M. Kern, Ser. No. 521,089, led March 9,1931, and assigned to the assignee of the present invention. It is to beunderstood that the rigid spindle may be employed with the automatichead provided on the tool described in the above mentioned applicationand may vbe continuously rotated. When inserted within the bore thehoning elements 48 will be in a collapsed position and after penetratingthe bore a predetermined distance will be automatically expanded to havethe elements moved into contiguous relation to the side of the cylinderbore. After the honing operation the upward movement of the toolcollapses the element before they protrude a predetermined distance fromthe cylinder bore, to thereby prevent the marring of the nish of thebore or damage to the abrading elements. In any application, theabrading elements have an opportunity to adjust themselves relative tothe spindle both by tilting about the camming member 4I and by effectingthe centering ofthe camming member relative to the spindle which may beslightly 01T center relative to the center of the cylinder bore.

While We have described and illustrated but a single embodiment of ourinvention it will be apparent to those skilled in the art that variouschanges, omissions, additions and substitutions may be made thereinwithout departing fromthe vspirit and scope of our invention, as setforth in the accompanying claims.

We claim as our invention:

1. A honing tool including, in combination, a unit spindle, expansibleabrading elements tiltably mounted for radial movement on saidv spindle,a spring associated with the lower ends of said elements for biasingthem inwardly toward the spindle, and a spring of less tension than saidrst spring associated with the upper ends of said elements for biasingthem toward the spindle.

2. A honing tool including, in combination, a unit spindle, expansibleabrading elements mounted on said spindle, a spring associated with thelower ends of said elements for biasing them inwardly toward thespindle, .a spring of less tension than said rst spring associated withthe upper ends of said elements for biasing them inwardly about thespindle, and a guide plate at the end of said spindle of substantiallythe diameter of said elements.

3. A honing tool including, in combination, a unit spindle, expansibleabrading elements mounted on said spindle, a spring associated with thelower ends of said elements for biasing them inwardly toward thespindle, and a spring of less tension than said rst spring associatedwith the upper ends of said elements for biasing them inwardly about thespindle, and a guide plate having sloping side walls and secured to theend of the spindle for guiding the end of the tool into a cylinder to bebored.

4. A honing tool including, in combination, a driving member, anabrading head supported by said driving member, means for expanding saidabrading head, and means for causing one end of said head to expandbefore the other when the head is unconflned and expanded.

KIRKE W. CONNOR. ALBERT BLEASDALE.

